(a) Technical Field
The present invention generally relates to a method for improving stain resistance and stain removal efficiency of fabric, particularly to a method for improving stain resistance and stain removal efficiency of fabric using a fluorine-based resin, preferably in combination with a crosslinking agent. More particularly, the present invention relates to a method for improving stain resistance and stain removal efficiency of fabric using a perfluoroalkyl acrylate copolymer and an isocyanate crosslinking agent.
(b) Background Art
Fabric clothes, and fabrics used in chairs, car seats and the like are often stained, for example by oils from the human body, food oils and dust in the air. Generally, products with blotted stains have a deteriorated external appearance, emit bad odors through proliferation of microorganisms, and impair product durability.
Fabric stains may be prevented by making the fabric resistant to staining or making the once-attached stain easily removable. For example, in the case of a car seat, which is difficult to wash once installed in a car, it is particularly important to make the fabric resistant to staining. Thus, vehicle manufacturers have set up their own stain standards for car seats to perform stain resistance and stain removal efficiency tests. In North America and Europe, stain removal efficiency is considered more important than stain resistance. However, in Korea, more emphasis has been put on stain resistance.
Conventionally, fluorine-based resins have been used for anti-stain processing of fiber. For example, Korean Patent No. 10-0105205 describes a method of preparing soil-resistant synthetic fiber using a perfluoroalkyl group-containing compound. However, this method requires an additional process for fiber preparation and, thus, has a disadvantage to be applied in industry. Therefore, it appears more advantageous to confer stain resistance after a fabric is prepared. In general, the anti-stain processing is carried out by covering the surface of fiber with a thin film using a fluorine-based polymer and greatly lowering surface free energy, while maintaining the rough fiber surface smooth, in order to minimize staining by oils. A method of treating fabric with an antifouling agent having a perfluoroalkyl group has been proposed, for example, in Japanese Patent Publication No. H9-324173, Korean Patent No. 10-0227100 and U.S. Pat. No. 5,578,688. However, these methods do not provide the properties required for high endurance, including stain resistance after abrasion, combustibility, frictional coloration, colorfastness, hardening, yellowing, or the like.